1. A 10-year-old boy undergoes a distal pancreatectomy for a 6 cm mass in the tail of the pancreas. Gross examination reveals a well-circumscribed, lobulated mass with a soft, fleshy consistency. Microscopically, the tumor demonstrates a solid and acinar pattern, with a hypercellular stromal component. Squamoid nests are present. What is the most likely molecular genetic finding in this tumor?